SEE THE LIGHT, SAVE THE ENERGY

If you had the potential to save thousands of dollars, would it be worth the effort to investigate it? Of course it would, and as a good steward of God’s grace we owe it to ourselves to consider the efficient use of energy for lighting our houses of worship.

The vast majority of church buildings in North America are more than twenty or thirty years old, and they were built in a time when energy was cheap and plentiful. Back then, energy efficiency wasn’t even on the radar. Even many of today’s modern buildings don’t take full advantage of the available technology to make the most of the energy they use. Technology is advancing so rapidly that two or three years can make a significant difference. Still, there is ample opportunity today to upgrade not only your platform lighting, but also the lighting in your sanctuary and the exterior of your building.

Take, for example, a church in Houston that recently underwent a lighting renovation. It was originally built in the early 1970s, and although the lighting was upgraded in the mid-1980s, the three-thousand person capacity sanctuary was a prime example of how newly developed technology can save enormous amounts of energy and money.

FLUORESCENT TECHNOLOGY
One of the prime areas of opportunity for improving energy efficiency was found in the lighting of the art glass windows. Inside the sanctuary were four very large stained glass windows, only one of which is open to the outside and lit by natural sunlight. The other three are interior windows and require artificial backlight to illuminate the beautiful colored panes of glass. They were originally installed in the 1970s and the means of lighting them was terribly inefficient; they were backlit with 190 1000-watt cyc lights.

In defense of the original lighting design, it worked very well and was not inappropriate at the time of the original installation. The cyc lights provided plenty of white light to uniformly backlight the windows and they could be dimmed with theatrical dimmers controlled by the lighting console. And at that time, the cost of electricity was at a historical low according to the U.S. Energy Information Administration Annual Energy Review 2006. This lighting scheme served its purpose well for decades.

But one-hundred-and-ninety kilowatts is more power than the average touring rock concert uses! It was an energy hog. In addition to the excessive amount of energy it uses, it also generates a tremendous amount of heat which has to be removed by the heating, ventilation, and air conditioning system (HVAC). Lastly, maintaining 190 fixtures scattered throughout the ceiling and among catwalks, some of which are not terribly easy to access, is a drain on resources.

When the lighting was redesigned, the original idea was to replace all of the cyc lights with high efficiency fluorescent lights. The new T5 fluorescent lights are surprisingly efficient and they are available in a number of color temperatures, including a “warm” light that approximates incandescent lights like the cyc lights they were to replace.

Let’s face it; most of us have had bad experiences with fluorescent lights. But those flickering, greenish headache-makers are all but a thing of the past. The newest technology is more compact, much more efficient, and better at rendering colors.

The T5 fluorescents were mocked up to evaluate their performance but they were ultimately rejected, not because of flickering, color rendering or any of the other reasons that you might think. They were rejected because they have one flaw – they can’t fade all the way to black. Yes, you can dim fluorescent lamps with specially designed ballasts, but they can only dim to 1% or 10%, depending on which ballast is used, and then they blink off. In many applications that would not be an issue but in this case it was. The video department nixed them because they wanted the ability to fade to black smoothly.

LED TECHNOLOGY
The rejection of the fluorescent fixtures was quick to overcome because there are several other options in today’s lighting market. One of the most obvious is LED technology. LEDs are just reaching the point where they are bright enough to replace conventional lights in many – but not all – applications and they’re getting better with each passing year. Right now, LEDs are excellent options for washing large areas with colored light, highlighting objects like truss or columns, and for task lighting. Although today’s LEDs are not quite ready for general stage wash, by the time you read this, they will be that much closer.

For this particular application, the 1000-watt cyc lights were replaced one-to-one with a three-cell LED cyc fixture. The resulting electrical load was reduced almost 68% from 190 kilowatts to 61.6 kilowatts and the thermal load was reduced from 648,307 British Thermal Units (BTUs) to 210,051 BTUs.

If the windows were lit up an average of 20 hours per week, then the energy consumption for the lighting alone would go from 197,600 kW-hours to 64,022 kW-hours. Assuming a cost of 9.86 cents per kW-hour for electricity, then the annual savings in electricity would be over $13,000. That’s not including the demand factor, which is a common charge the electric company adds to your bill every month to account for the amount of electricity you use at any one time.

In addition to the savings realized from the reduction of electrical consumption, there is also a significant decrease in the amount of heat produced by the LED fixtures. And that translates into more electrical savings because the HVAC doesn’t have to work as hard to remove the heat. The amount of heat that a lighting instrument produces is directly related to the wattage of the fixture. Every watt represents about 3.4 BTUs and in order to maintain the same temperature in the building, this heat has to be removed by the HVAC. The amount of electricity that takes depends on the efficiency of the A/C units. In the case of 30 year-old construction, we can assume a lower Seasonal Energy Efficiency Rating (SEER) of about 10, which is a relatively low rating by today’s standards. At an average of 20 hours per week of use, the annual savings in electricity due to the lower heat value of the LED fixtures would be about $4,500.

But before we start counting the chickens in our electrical closets, we should mention that LEDs aren’t the Holy Grail of lighting. True, they have much to offer, but they aren’t without their own drawbacks, the biggest of which is probably their cost. Although the cost of LEDs is steadily dropping while the brightness is steadily increasing, they are still considerably more expensive than conventional lighting. While a 1000-watt cyc light in today’s market might cost two or three hundred dollars, an LED batten can cost anywhere from $1000 to $3000 or more.

There’s also the issue of dimming and color rendering, neither of which an LED can do as well as incandescent lamps. With most LED fixtures, if you look very closely you can see individual steps of dimming. Incandescent lamps have a sort of dimming inertia but LEDs are so responsive that each step is almost a jump. They also have a discontinuous spectrum so they tend to render color differently than incandescent. There are, however, some LED fixtures with up to seven colors to better approximate the incandescent spectrum that are better at color rendering.

But as the numbers indicate, the operational savings can be significant. And as an added bonus, the quality and quantity of colors available from a red-green-blue (RGB) color wash LED fixture is typically very good. And lastly, LEDs have a life of 50,000 to 100,000 hours, which, at 20 hours of use per week, will last several decades. Check the math and you’ll be pleasantly surprised.

ENERGY EFFICIENCY FOR EVERYONE
Of course, not every church has interior stained glass windows this large. But one thing that every church large and small does have is lighting for general illumination. And there’s a good chance that there is an opportunity to realize more energy savings there as well.

Take a look at the house lights in your sanctuary and evaluate them on the basis of energy efficiency. If they are incandescent lamps then, chances are, you could replace them with much higher efficiency fixtures. If they are the old style T12 lamps (the “12” indicates that the diameter is 12 eights of an inch, or 1.5 inches in diameter) then you can do much better by switching to T5 lamps and newer high efficiency ballasts.

Compact fluorescents are another viable option, depending on your dimming requirements. Although they can dim to 10% with specialized ballasts and to 1% with more expensive specialized ballasts, they do flash off at the tail end of the dimming curve. But since most house lighting is seldom fading to black, this may not be an issue. There are also multi-circuit compact fluorescent fixtures available that “dim” in steps by turning off one or more of the circuits in a single luminaire at a time. If it’s designed correctly, a lighting system with multi-circuit CFLs is a relatively inexpensive way to convert your older, inefficient house lighting to a more efficient system with stepped dimming.

THE BOTTOM LINE
In the same church with the stained glass windows, the house lights were 1000-watt PAR lamps – 168 of them. A PAR lamp produces a lot of light but it also produces a lot of heat, which is a good indicator that it is not very efficient. If those 168 PAR fixtures are replaced by a more efficient 575-watt fixture, the energy consumption would be cut by 43%, resulting in a savings of about $10,000 annually without any decrease in lighting levels.

In addition to the dollar savings, there are several more reasons to upgrade to more efficient lighting. It turns out that about half of the world’s electricity is produced by coal-burning power plants. In addition to the dollar savings, upgrading the lighting for the stained glass windows and the house lights would result in an annual savings of about 119 tons of coal. The same energy reduction also results in annual savings of 218 tons of carbon dioxide, as well as the reduction in the amount of arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, molybdenum, radium, selenium, vanadium, and zinc that would be released into the atmosphere.

Given the current economic expansion in Asia and many other parts of the world, the demand for electricity is likely to increase for some time to come, and that is likely to put inflationary pressure on the cost of electricity. That’s the bad news. The good news is that new technologies are being invented and improved every day. General Electric is currently working on a high-efficiency incandescent lamp (HEI) that is supposed to rival CFLs in efficiency. The inventor of the ETC Source Four fixture, David Cunningham, has a patent on a method to improve the efficiency of an incandescent lamp to rival that of a CFL or LED. There is also an effort to build a new highly efficient incandescent lamp filament called a tungsten lattice that will also significantly improve the efficiency of incandescent lamps. None of these technologies are available today but they are very promising for tomorrow. And that’s to say nothing of those technologies about which we know nothing yet.

Not everyone agrees that global warming is a man-made problem or that we can affect it by being more environmentally conscious, but the savings that can be realized by using more efficient lighting are indisputable. Take a close look at your lighting and consider the possibilities. It might surprise you.